This invention relates to nestable and extendable pouring spouts for containers and in particular to spouts having flow venting means for smoothing liquid flow from the container, and pressure venting means to equalize internal container pressure with atmospheric pressure.
One aspect of this invention is the provision of flow venting means to improve liquid dispensing.
During dispensing the loss of liquid volume and pressure inside the container is replaced with air entering the container. Liquid pulsations may result when the liquid flowing out of the container must share the same path with air entering the container. Extendable pour spouts connected to containers are particularly susceptible to liquid pulsations as the liquid flow generally converges and outlets through a narrow nozzle or neck. The incorporation of self-venting or flow venting devices assist the entry of air into containers and to smooth the outflow of the liquid contents is a common practice. Smooth pouring may also be obtained with unvented containers by carefully controlling the angle of pour so that the spout nozzle never flows full, thereby maintaining an air passage through the spout into the container. Establishing and maintaining this proper pouring angle can be difficult or unmanageable because of the high initial liquid level and because of the weight of full containers.
Installing a separate air vent in the container which is opened to allow air to enter above the level of the liquid is another common practice, particularly for viscous liquids. The container may or may not have a separate cover. However, the provision of separate vents are generally more costly to manufacture, create the possibility of potential leaks and require more time to open and reseal the second closure. In the absence of venting means provided by the container manufacturer, a common practice is for the user to pierce a vent hole in the container cover opposite the location of the pour spout. The pierced vent hole, if not resealed tightly, may expose the container contents to contaminants.
Another goal of this invention is an improved method of closure insertion and attachment to the container. In the manufacture of plastic containers, production efficiency may be improved by installing the closure to the container as soon as it is molded. These hot molded plastic containers lack the rigidity of cold containers, so closure insallation forces must be low. Hot plastic containers may be molded oversize to compensate for shrinkage as they cool. Closure which have a means of self alignment with the container opening can improve the efficiency of installation operators and machinery. Larger lead in angles on the closure body skirt help capture the container rim. Internal locking means that resist external tampering to remove the closure is also desirable.
Prior art spouts have been fitted with self-venting (flow venting) devices for maintaining an air passage through the spout regardless of the angle of pouring. Prior art pour spouts have also been equipped with pressure venting means. Pour spout closures may be equipped with both flow venting means and pressure venting means depending upon the application.
For example central tube type flow ventilation devices are illustrated in U.S. Pat. Nos. 3,040,938 and 4,295,583 which illustrates a vented pour spout wherein a venting unit is rigidly secured to the inside surface of a flexible pour spout. This venting unit permits the entry of air into the container so as to enable a smooth flow of liquid from the container by way of the pour spout.
These prior venting devices are essentially tubes mounted concentrically within the neck of the spout so as to form an annular air space between the tube and the neck. The base of the tube is fitted with a flange having a plurality of small peripheral channels, which flange is drawn up against the base of the spout when the spout is in the extended orientation. In this orientation, air may enter the container through the annular space and peripheral channels while the fluid exits through the central tube.
A disadvantage associated with this structure concerns the self-venting attachment which is bonded to the neck portion of the spout and adds to the overall axial length of the closure when in the nested position, thus increasing handling packaging and shipping costs of such spouts. It would be desirable to provide a nestable an extendable pouring spout with self contained venting means which maintains the compact configuration of such spouts which was a goal of U.S. Pat. Nos. 4,555,938 and 4,618,078.
Centrally restricted aperture flow vented devices are illustrated in U.S. Pat. Nos. 4,555,048 and 4,618,078.
These vented nestable pouring spout generally illustrate devices having a plurality of circumferentially spaced ears attached to the spout and extended therefrom. The ears extend inwardly substantially perpendicular to the longitudinal axis of the neck portion of the spout when the spout is in the extended orientation; the ears define a central restricted flow aperture for the outflow of liquid and the adjacent ears defines a peripheral vent opening therebetween for the inflow of air.
One disadvantage associated with this self-vented closure is the location of the xe2x80x9cearsxe2x80x9d in close proximity to the annular recess where the closure is mounted onto covers during installation. The ears and rib extensions may inadvertently be caught on the outside of the annular rim of the cover opening during installation, resulting in a spout that may leak.
A cone shaped internal attachment flow device is shown in U.S. Pat. No. 4,295,583. The nestable self-venting attachment is a truncated cone in shape. The wide end of the cone is light pressed fit onto a retracted pour spout closure with a metal attachment ring. A thin flange on the wide end of the cone is captured behind the bead of the cover opening during installation, permanently securing the cone shaped vent. The base of the cone has a flat portion and a re-entrant cylinder which defines the central nozzle to control and channel the liquid flow. There are a number of small rectangular vent openings evenly spaced around the circumference of the cone. These vents are located close to the wide end of the cone, which would place the small vent openings near the inner surface of the cover when the closure is installed.
The vent attachment does not move when the pour spout is extended, and the vent holes and the central nozzle maintain their position relative to the inside of the cover.
A disadvantage of this design is the reliance on the small rectangular vent openings to empty the container once the liquid level has fallen below the level of the central nozzle.
The cone sidewall becomes a sump which blocks liquid and may result in longer emptying time or lost product.
Prior art pour spout closures equipped for pressure venting are commonly fitted with buna rubber valves or the like. The buna valve is inserted through an opening in the closure to create a restricted vent path. The valve head has a rubber annular lip which in the normal position creates a liquid tight seal. Pressure build up forces the rubber annular lip to lift and open the vent path. The buna valve will reclose the vent path once the pressure has dropped. One problem with buna pressure valves is that it is uni-directional and can only relieve pressure in one direction. Closures equipped for pressure or vacuum venting are manufactured and sold separately for specific applications. It would be desirable to have a bi-directional vent.
Prior art pour spout closures equipped for relieving pressure may alIernately be fitted with an orifice covered with a gas permeable microporous membrane made of teflon or the like.
Buna and microporous vents may become fouled and inoperable due to liquid in the container wetting the vent and subsequen build up of crystals or other deposits which foul the vent. For example sodium hypochloride in bleach tends to dry as crystals which can foul vents. Sugar crystals from food products may have a similar effect. A baffle which blocks the splashing of the liquid onto the pressure vent would correct this problem.
Closures that are partially submerged in the liquid may have the liquid level in the nozzle area rise due to internal pressure. The pressure vent then becomes flooded with liquid under pressure. Liquid may eventually escape to the outside of the continer. A baffle which would block liquid from direct contact with the pressure vent would be an improvement over the prior art.
Prior an pour spout closures are attached to containers with various methods including press in interference fit, ultrasonic welding, insert molding, metal crimp rings and plastic lock rings. A closure with two position lock ring is illustrated in U.S. Pat. No. 5,788,100. The plastic closure has a cap with outer locking ring formed integrally and co-axially. The closure spout skirt first moves over the container bead and back into a partially relaxed position before the locking ring is moved into the locking position.
The closure disclosed in U.S. Pat. No. 5,788,100 works exceedingly well, however a further improvement on this prior art would be to widen the outer flange on the skirt so that the closure could more readily slide over the rim and bead of the container opening. This a particular advantage when installing closures on hot molded containers. The container opening is typically molded oversize to allow for plastic shrinkage as the plastic container cools.
A further improvement in this prior art would be to incorporate internal locking means in the flow venting baffle to discourage removal of the closure by tampering or by impact. The addition of baffle guide ribs to help guide the closure into coaxial alignment with the container opening would further improve the assembly operation.
It is an object of this invention to provide flow venting means to improve liquid dispensing.
It is another object of this invention to provide an improved method of mounting pressure vents in closures, and a method for blocking the liquid in the container from directly contacting the pressure vents.
It is another object of this invention to provide improved closure installations and locking features.
It is another aspect of this invention to provide a closure for a container, the closure comprising an inner baffle, body spout and cap, the baffle have surfaces from restricting liquid flow through the spout opening.
Another aspect of this invention relates to a closure for a container comprising a spout for dispensing liquids from said container, said spout engageable with said container at one end thereof; an internal baffle having surfaces for restricting liquid flow through the spout opening, and said internal be having a plurality of orifice for regulating liquid passage out of the container and air passage into the container.